const { CleanWebpackPlugin } = require('clean-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const path = require('path')

module.exports = {
  mode:'production',
  entry: './src/index.ts',
  output: {
    path: path.resolve(__dirname,'./dist'),
    filename: 'bundle.js',
    environment:{
      arrowFunction: false,
      const: false
    }
  },
  module: {
    rules: [
      {
        test: /\.ts$/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: [
                [
                  '@babel/preset-env',
                  {
                    targets: {
                      'chrome':'58',
                      'ie':'11'  
                    },
                    corejs: '3',
                    useBuiltIns: 'usage'
                  }
                ]
              ]
            }
          },
          'ts-loader'
        ],
        exclude: '/node_modules/'
      },
      {
        test:/\.less$/,
        use: [
          'style-loader',
          'css-loader',
          {
            loader: 'postcss-loader',
            options:{
              postcssOptions: {
                plugins: [
                  [
                    "postcss-preset-env",
                    {
                      browsers: 'last 2 versions'
                    }
                  ]
                ]
              }
            }
          },
          'less-loader'
        ]
      }
    ]
  },
  plugins: [
    new CleanWebpackPlugin(),
    new HtmlWebpackPlugin({
      template: './index.html'
    })
  ],
  resolve: {
    extensions: ['.ts','.js']
  }
}